Paperboard carton with sift-proof opening device and reclosure



J.C W;i5

Aug. 7, 1956 N. KLEIBER 2,

PAPERBOARD CARTON WITH SIFT-FROOF OPENING DEVICE AND RECLOSUREJ Filed Feb. 17, 1954 2 Sheets-Sheet 1 I N V EN TOR. NORM/1N M055? ATTURNE X5 Aug. 7, 1956 N. KLEIBER PAPERBOARD CARTON WITH SIFT-PROOF OPENING DEVICE AND RECLOSURE 2 Sheets-Sheet 2 Filed Feb. 17, 1954 INVENTOR.

by NORMAN KLE/BER United States Patent PAPERBOARD 'CARTONWITH SIFT-PROOF :1. OPENING DEVICEAND- RECLOSURE "*1: Norman Kleiber, Upper Nyac'k; Y.;a'ssig'nor"to Robert .1 a om an c, w YQr i a corporation of Delaware Applieation February '17, 1954, Serial No. 410,754 r 3 Claims. el: m m 1 closing the opening or pouringdevice .Generallyspeakin g th-e. easier the carton can beopened o r made ready for pouring of its contents, the less itis proQf, against sifting,o f.,its contents during shipment and .handling. Myjinvention is directed to .the particular proble' providing an opening and'reclosure device which. tremely easy to operate, yet which enables ,ietent onfof adequate sift-proof construction and which well adapted for handling in conventional packaging machinery.

Summary My improved carton and carton blank comprises four side panels,-an.end flap adjoining. each .of the side panels, two opposedxendflaps (usually the narrower ones) being foldableinwardly to forminner end flaps andjtheremaining two end flaps being foldable inwardly outside of the folded inner end flaps to form ,outerendflaps, a weakened line in the outer end flaps extending across the top of the carton parallel to the fold lineof one of the inner end flaps,.this weakenedline-being located.wh ere -.it is overlappedvslightlynby thev end' of thednnenend flap just mentioned. .A second weakened lines extends t at right angles to the first anddividesin, two thatportion .of the outerendflaps which overlies. the inner endiflap to:-which'nl have. referred. .This inner2 end ifiap'.- is,,ad-

-hesive1y secured totheadjacent outerend flap, structure over an .area lyingimmediately. adjacent the, iqlddl ine. Other features of my invention will appear in the following Description In the drawings, wherein I have shown the best mode contemplated by me of carrying out my invention:

Fig. 1 is a perspective view of my carton in its preferred form and as a completed package.

Figs. 2 to 7 inclusive illustrate the steps of opening and reclosingthe carton of Fig. 1, thus:

Fig. 2 shows the initial opening step of pressing inwardly to break open the carton.

Fig. 3 shows the second opening step.

Fig. 4 shows the third opening step.

Fig. 5 shows the first step in closing the carton.

Fig. 6 shows the second step in closing the carton.

Fig. 7 shows the reclosed carton.

Fig. 8 is a detail vertical sectional view of the carton, before opening.

Fig. 9 is a similar view, after the carton has been opened and reclosed.

as shown at 30 for ease in performing the reclosing" opera- 2,757,850 ljatented Aug. 7, 1956 ice Fig. 10 is a face view of. the blank from which the carton of Eigs. l to 9 is formed. v

Ll is a detail vertical sectional view of a modified form of opening andreclosing device, illustrating the first opening step, i. e. in this respect corresponding to Fi w. i. I v, Referring to Figs. 1 and 10, my improved carton and carton blank comprisesfour side panels 12 13, 1 4, 15 an endflap adjoining each ofthe side panels (.end'flaps 1 6, 1,7, 1 8, 19 respectively)., two opposedend flaps 17, 1 9 being foldable inwardly to form inner end flaps, the remaining'two. end flaps 16, 18 being foldable inwardly outside of the foldedinner end flaps. to forirr outer end flap s a weakened .line Z O, 20" in the outer endflaps extending across the. top of the carton parallel to the fold line 2 8 e f inner end fl ap 17, the weakened: unezp, 2Q being located where it .is overlapped "s lightly .by the end inner end fiap 17, and. a second weakened line 2 1, 2 1 extending at right anglesfrom the first weakened line 2 0,:,and dividingin two that portion of .the.,outer end flaps "16,, 18 which overlies'inner 'end 'flap 17 The several panels 12, 13,14, 15,'an'd end fiaps16,'l17,f18, rage defined in the blank (Fig. 10) by the usual score lines ZS and cut lines g9, thescpre lines determining the fQl lin s .b t n t e. ve a pa el ndl fl s, Gl e lap. extension 2 6. and panel. llarelfold edlover against panels and 14, and panel 15 is" folded oyer panel 14 by bending on foldlines between panels 12. and 1 3 and .1 nd 1. 9 i t ue 11 .Ilfi ms adhs v l' s'ej- .11 'Qd..- .]t v Q t s e.Pan 1-' .5. 9 iire tu ie th fl fi d g u d n ,1. 1i weakened lines 20,10, 21, 21' maybe formed as perforationsor as interrupted cut lines In my. preferred construction weakened lines 20, 21 in the. outerrnost flap 18 are formed by perforations, and'weakened lines 20' .21 in flap 16 areforrned by interruptedbut lines. I have found that this particular arrangement com- ;bines strength inthe outermost flapwith ease offbreak'ing openthe carton at theweakened lines when ready for use. 7, Inner end flap 17 has a U-shaped out line 22 forming tab 13which can be. pressed inwardly to provide a finger opening. The corners'of flap 17. preferably...are more d tion to be described. 7 a

":An important feature of my opening device and reclosure is that inner end flap 17 is adhesively secured to the adjacent outer end flap structure over an area 27 lying immediately adjacent the fold line 28 of flap 17; i. e1. the glued. area extends. from this foldline .to the extent indicated at a in Figs. 3v and 10. This provides a ,goodsealbetween theiinnenand outer end flapsflwhile leaving flap 17 free over most of its area, making it very easy to break open the carton by pressing inwardly in the direction and general location indicated by the arrow b in Fig. 2. It is particularly important to have a glued area lying immediately adjacent the fold line of the inner flap because, after the carton has been filled there usually is no support underneath the flaps during the sealing operation except near the edges and corners of the carton. Therefore, if the glued area lies inwardly of the fold line, the inner end flap tends to curl away, resulting in poor adhesion. This difficulty is increased by reason of the fact that the wet adhesive tends to make the inner flap curl away from the first folded outer flap. One of the opening and reclosure devices heretofore proposed possesses the disadvantage that in order to make it operable the glued area between the inner and outer end flaps must be located some distance inwardly of the fold line. This creates a serious problem in the packaging of finely powdered products such as soap powder, washing soda, cereals, etc., which can sift out through the corners during shipment and handling. This is a problem of long standing which results not only in loss of contents of the packages but in defacing the outer printed or lithographed surfaces of the carton. During shipment when cartons are disposed one on top of another, the usual jouncing action caused by unevenness in roads or road beds in transportation by truck or rail, results in repeated inward pressures on the sides of the carton, producing what may be described as a bellows action which will blow out the fine contents of the cartons through the tiniest cracks; hence the great importance of preserving a strongly sealed area adjacent the fold line of the inner end flap. According to one mode of carrying out my invention, the outer surface of inner end flap 17 is treated with glue repellant ink except for the area 27 of the flap which lies immediately adjacent the fold line.

Referring now to Figs. 2 to 9 inclusive, I shall describe the operation of my improved opening device and reclosure. Fig. 8 shows the sealed carton before opening. The first step in opening the carton is to press inwardly in the direction and general location indicated by the arrow b in Fig. 2. This ruptures the weakened lines 20, 21, 21', dividing in two that portion of the outer end flaps which overlies inner end flap 17 to produce flap sections 24 and 25. This is accomplished by pressing inwardly with the thumb or forefinger at the inner corner of section 24 or 25, or both. When the perforated and cut lines of the outer flaps have thus been broken through, the glued area 27 will break loose and the two sections 24, can then be opened in shutter fashion as indicated in Fig. 3. Inner flap 17 is now free and can be opened as indicated in Fig. 4 by inserting the forefinger into the opening provided by pressing in tab 23, and pulling upwardly and outwardly. The carton is now ready for use.

To reclose the carton, the first step is to fold inwardly the flap sections 24 and 25 as indicated in Fig. 5. Then flap 17 is brought around as shown in Fig. 6, and its end tucked into the slot provided at the edges of sections 24 and 25. Figs. 7 and 9 show the reclosed carton in which the edge of flap 17 lies underneath the edge of the unopened portion of the carton top. Flap sections 24 and 25 press upwardly on flap 17 to maintain the latter in this tucked position.

In Fig. 11 I have illustrated a slightly modified construction in which the weakened line 20 of the outermost end flap 18 is slightly offset with respect to the corresponding weakened line 20 of the companion outer flap 16. Fig. 11 illustrates the first opening step in the modified construction, i. e. in this respect corresponding to Fig. 2. This offsetting of weakened lines 20 and 21 strengthens the construction and further helps to prevent sifting of the contents but does not interfere appreciably with the opening and reclosing operations.

A further advantage of my carton construction is that,

4 because weakened lines 20, 20', 21, 21' meet at a central point of the carton top, the corners of flap sections 24, 25 are free to be pressed inwardly, making it quite easy to open the carton. Also, since weakened line 21, 21' is well removed from the lateral edges of the carton top, there is very little tendency for the flaps 16 and 18 to break along such weakened line during the folding of these flaps in the packaging machine. This is helpful in avoiding sifting problems, because it insures a clean sharp fold at the fold lines of flaps 16 and 13, avoiding any tendency to pucker or to leave a channel through which powdered contents of the carton could sift.

The terms and expressions which I have employed are used in a descriptive and not a limiting sense, and I have no intention of excluding such equivalents of the invention described, or of portions thereof, as fall within the purview of the claims.

I claim:

1. A carton of paperboard and the like comprising four side panels, an end flap adjoining each of the side panels, two opposed end flaps being foldable inwardly to form inner end flaps and the remaining two end fiaps being foldable inwardly outside of the folded inner end flaps to form overlapping outer end flaps, said inner and outer end flaps when folded comprising the top of the carton, a weakened line in the outer end flaps extending across the top of the carton parallel to the fold line of one of the inner end flaps, said weakened line being located Where it is overlapped slightly by the end of said one inner end flap, and a second weakened line extending at right angles from the first named weakened line and spaced from the fold lines of said outer end flaps, said second weakened line dividing in two that portion of the overlapping outer end flaps which overlies said one inner end flap.

2. A carton as defined by claim 1 in which said one inner end flap is adhesively secured to the adjacent outer end flap structure over an area extending along the length of said fold line.

3. A carton as defined by claim 1 in which the firstnamed weakened line of the outermost of said overlapping outer flaps is slightly offset with respect to the corresponding weakened line of the companion outer flap.

References Cited in the file of this patent UNITED STATES PATENTS 1,917,402 Stevenson July ll, 1933 2,044,979 Greve June 23, 1936 2,132,925 Bensel Oct. 11, 1938 2,162,556 Lagaard June 13, 1939 2,287,520 Freshwaters June 23, 1942 2,345,978 Hultin Apr. 4, 1944 2,351,812 Guyer June 20, 1944 2,588,996 Snyder Mar. 11, 1952 

